Subscribers access, i.e., receive and transmit information to, a telecommunications network through various means, such as a hand held telephone or a personal computer. Numerous types of technologies presently exist, and continue to be developed, to provide for access with respect to a telecommunications network.
Certain of the access technologies concern wireless access to a telecommunications network.
Analog wireless technologies, such those which follow the Advanced Mobile Phone Service (abbreviated AMPS), Total Access Communications System (abbreviated TACS) and Nordic Mobile Telephone (abbreviated NMT) standards, have been used extensively in the past to provide wireless communications services to subscribers. As operators of analog wireless systems desired to add subscribers, more radio channels were needed to accommodate those subscribers since those systems allocated radio channels on a per subscriber basis. To solve this dilemma, digital wireless technologies were developed to allow for capacity increases by allowing more subscribers to share the same radio channel spectrum.
Digital wireless technologies solve some of the deficiencies of analog wireless technologies. Digital wireless technologies do not, however, use a common approach to divide the radio channel spectrum. Rather, one digital wireless technology, known as Time Division Multiple Access (abbreviated TDMA) divides a radio channel into time slots that are individually used by a subscriber unit. Yet another digital wireless technology, known as Code Division Multiple Access (abbreviated CDMA) divides the radio channel spectrum into wideband digital signals that carry different coded channels that are each identified by a unique pseudo-random noise code. Still another digital wireless technology, known as Frequency Division Multiple Access (abbreviated FDMA), increases the number of radio channels within the radio channel spectrum by decreasing the bandwidth assigned to each channel and provides a control channel that coordinates a subscriber unit's access to a voice channel. There presently exists numerous different standards and protocols that use one of the aforementioned different digital wireless technologies yet impose inconsistent requirements. Many standards are accepted in certain regions of the world but not others. There are, for instance, several standards associated with TDMA technology.
Wireline and other technologies also offer subscribers access to a telecommunications network. For example, fixed wireless local loop technology has become an alternative to mobile cellular technology, especially in areas where no wireline infrastructure exists.
Designers and manufactures of cellular telecommunications systems have, and continue to, develop telecommunications systems that are uniquely designed to be consistent with a particular access technology or standard. For example, manufacturers often offer distinct telecommunications systems for analog mobile cellular systems, digital mobile cellular systems, fixed wireless local loop systems, and wireline systems. Such telecommunications systems often use inflexible, monolithic conventional software applications, having thousands of interdependent and loosely organized lines of code, and are designed without regard for use with other technologies. Such conventional telecommunications systems also are typically constructed by distinct equipment and components that are interconnected together. Conventional telecommunications systems therefore do not provide for multiple access technologies or standards and cannot be readily modified to accommodate another access technology or standard. As a result, telecommunications systems are undesirably limited. For example, a conventional wireless telecommunications switching system is not able to receiver a call from a TDMA mobile subscriber and direct that call to a CDMA mobile subscriber. Rather, at least two conventional telecommunications systems would be needed.